This invention relates to a start boosting device for an internal combustion engine and more particularly to an improved enrichment device for an internal combustion engine.
It is well known to supply enrichment fuel to an internal combustion engine under certain conditions. For example, enrichment fuel is normally provided so as to assist in starting and/or for cold running warm up. Generally the enrichment fuel is supplied to the engine only at atmospheric or slightly greater than atmospheric pressure. However, the supply of enrichment fuel at these low pressures is not always sufficient to insure the desired running or starting of the engine. Although pumping devices have been incorporated for assisting in the supply of enrichment fuel, these pumping devices generally are "one shot" types of devices that only provide a finite amount of fuel under pressure. These devices also are not fully satisfactory.
Even if enrichment fuel is supplied to the engine at an elevated pressure, this may be not be sufficient so as to insure proper engine operation. For example, if the enrichment fuel supply is pressured, the mixture supplied to the engine may be too rich.
It is, therefore, a principal object of this invention to provide an improved enrichment system for an internal combustion engine.
It is another object of this invention to provide an enrichment system wherein both fuel and excess air are supplied to the engine in response to the desired condition.
Where both additional fuel and air are supplied to the engine and the fuel is pressurized, it must be insured that the pressurized fuel does not flow out of the air enrichment system rather than to the engine. It is, therefore, a still further object of this invention to provide an improved arrangement for supplying both excess fuel and air to an engine under certain conditions and wherein the pressurized fuel cannot flow into the excess air system.